In many of the examples, opts is included as a parameter for callbacks that are not invoked by the power-up developer, but by Trello.
I did a little bit of testing, and it seems like in some cases, the opts that are passed by trello include a context property with the same data as t.getContext(), plus a locale property.
Still seems like this is missing from the docs though… it’s unclear if opts is guaranteed to always have that shape, or if there are exceptions. Also, whether it is deprecated in favor of t.getContext() or not.
Oh my mistake, I was referring to a different opts called from a callback function that you pass like in this example. The properties in the opts parameter can change based on the capability you’re trying to make and should not be replaced with t.getContext() for all uses.